Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS4838215 A
Publication typeGrant
Application numberUS 07/184,357
Publication dateJun 13, 1989
Filing dateApr 21, 1988
Priority dateDec 21, 1984
Fee statusPaid
Also published asUS4741294
Publication number07184357, 184357, US 4838215 A, US 4838215A, US-A-4838215, US4838215 A, US4838215A
InventorsMakoto Yasuda, Syousabu Ura, Shuichi Nishimura, Isaya Matsuo, Masami Kato, Munehiro Sagata
Original AssigneeNissan Motor Co., Ltd., Aichi Machine Industry Co., Ltd.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Inertia supercharging induction system for multi-cylinder internal combustion engine
US 4838215 A
Abstract
In order to minimize the supercharging effect from the cylinder to cylinder and to maximize the efficiency of the inertia supercharging effect over essentially the whole engine speed range, first and second elongate collectors which communicate with separate banks of cylinders are interconnected at essentially their mid points by a connection tube having a selected length and cross-sectional area. An engine speed responsive valve disposed in the tube or pipe selectively induces the situation wherein quasi separate induction systems are defined for each bank of cylinders or a single enlarged system is established.
Images(7)
Previous page
Next page
Claims(12)
What is claimed is:
1. In an internal combustion engine:
a first group of cylinders, the ignition sequence of said first group of cylinders being discontinuous;
a second group of cylinders, the ignition order of said second group of cylinders being discontinuous; and
an induction system for supplying air to said first and second group of cylinders, said induction system comprising:
a first elongate collector section with which said first group of cylinders fluidly communicate via branch runners, said first collector section having first and second ends;
a second elongate collector section fluidly discrete from said first collector section and with which said second group of cylinders fluidly communicate via branch runners, said second collector setion having first and second ends;
a surge tank;
first and second induction conduits leading from said surge tank to said first and second collector sections respectively, said first and second conduits fluidly communicating with said first and second collector sections at the respective first ends thereof;
a connection passage leading from said first collector section to said second collector section; and
a valve disposed in said connection passage, said valve being arranged to assume a closed position wherein communication between said first and second collector sections is prevented and an open position wherein communication is permitted, said valve being arranged to change from said closed position to said open position upon the magnitude of a selected operational parameter of said engine exceeding a predetermined level.
2. An internal combustion engine as claimed in claim 1 wherein said first group of cylinders comprises three cylinders and said second group of cylinders comprises three cylinders.
3. An internal combustion engine as claimed in claim 1 wherein each of said cylinders includes a combustion chamber which communicates with the a runner via an induction port, said induction port having a predetermined cross sectional area.
4. An internal combustion engine as claimed in claim 1 wherein said engine has a predetermined displacement and wherein each of said collector sections has an internal volume which is greater than half of the engine displacement.
5. An internal combustion engine as claimed in claim 3 wherein the cross sectional area of said induction conduits is equal to or greater than 2.5 times the cross sectional area of said induction ports.
6. An internal combustion engine as claimed in claim 1 wherein the length of said connection passage is 0.33 to 1.5 times the length of a collector section.
7. An internal combustion engine as claimed in claim 1 wherein said connection passage has a cross-section which is smaller than the cross-section of the collector sections.
8. An internal combustion engine as claimed in claim 1 wherein said first and second collector sections are arranged side by side, and wherein said surge tank is elongate and is arranged to extend essentially parallel to the said collector sections, wherein said connection pipe as an essentially U-shape and is disposed flat on top of aid first and second collectors.
9. In an internal combustion engine:
a first group of cylinders, the ignition sequence of said first group of cylinders being discontinuous;
a second group of cylinders, the ignition order of said second group of cylinders being discontinuous; and
an induction system for supplying air to said first and second group of cylinders, said induction system comprising:
a first elongate collector section with which said first group of cylinders fluidly communicate via branch runners, said first collector section having first and second ends;
a second elongate collector section fluidly discrete from said first collector section and with which said second group of cylinders fluidly communicate via branch runners, said second collector section having first and second ends;
a surge tank;
first and second induction conduits leading from said surge tank to said first and second collector sections respectively, said first and second conduits fluidly communicating with said first and second collector sections at the respective first ends thereof;
a connection passage leading from said first collector section to said second collector section; and
a valve disposed in said connection passage, said valve being arranged to assume a closed position wherein communication between said first and second collector sections is prevented and an open position wherein communication is permitted, said valve being arranged to change from said closed position to said open position upon the magnitude of a selected operational parameter of said engine exceeding a predetermined level;
wherein said first and second collector sections are arranged side by side, and wherein said surge tank is elongate and is arranged to extend essentially parallel to said collector sections, wherein said connection pipe has an essentially U-shape and is disposed flat on said first and second collectors; and
wherein said first and second induction conduits are not equal in length and wherein the volumes of said first and second collector sections are different.
10. In an internal combustion engine:
a first group of cylinders, said first group of cylinders having a discontinuous ingition sequence; a second group of cylinders, said second group of cylinders having a discontinuous ignition sequnce; and
a naturally aspirated induction system for supplying air to said first and second group of cylinders, said naturally aspirated induction system comprising:
a first elongate collector section, said first section being fluidly communicated with the cylinders of said first group of cylinders, said first collector having first and second ends;
a second elongate collector section, said second collector section being fluidly communicated with the cylinders of said second group of cylinders, said second collector section having first and second ends;
an air cleaner;
a surge tank fluidly communicated with said air cleaner;
a throttle valve operatively disposed between said surge tank and said air cleaner;
first and second induction conduits leading from said surge tank to said first and second collector sections respectively, said first and second conduits fluidly communicating with said first and second collector sections at the respective first ends thereof;
a connection passage interconnecting said first and second collector sections; and
a valve disposed in said connection passage, said valve being arranged to be selectively openable in response to the value of an engine operational parameter exceeding a predetermined level.
11. In an internal combustion engine:
a first group of cylinders, the ignition sequence of said first group of cylinders being discontinuous;
a second group of cylinders, the ignition order of said second group of cylinders being discontinuous; and
an induction system for supplying air to said first and second group of cylinders, said induction system comprising:
a first elongate section with which said first group of cylinders fluidly communicate via branch runners, said first collector section having first and second ends;
a second elongate collector section fluidly discrete from said first collector section and with which said second group of cylinders fluidly communicate via branch runners, said second collector section having first and second ends;
a supercharger;
a surge tank in fluid communication with said supercharger for receiving air under pressure therefrom;
first and second induction conduits leading from said surge tank to said first and second collector sections respectively, said first and second conduits fluidly communicating with said first and second collector sections at the respective first ends thereof;
a connection passage leading from said first collector section to said second collector section; and
a valve disposed in said connection passage, said valve being arranged to assume a closed position wherein communication between said first and second collector sections is prevented and an open position wherein communication is permitted, said valve being arranged to change from said closed position to said open position upon the magnitude of a selected operational parameter of said engine exceeding a predetermined level.
12. In a supercharged internal combustion engine:
a first group of cylinders, said first group of cylinders having a discontinuous ignition sequence; a second group of cylinders, said second group of cylinders having a discontinuous ignition sequence; and
an induction system associated with a supercharger for supplying air to said first and second group of cylinders, said induction system comprising:
a first elongate collector section, said first section being fluidly communicated with the cylinders of said first group of cylinders, said first collector having first and second ends;
a second elongate collector section, said second collector section being fluidly communicated with the cylinders of said second group of cylinders, said second collector section having first and second ends;
a surge tank fluidly communicated with the supercharger;
a throttle valve, said throttle valve being disposed upstream of said surge tank;
first and second induction conduits leading from said surge tank to said first and second collector sections respectively, said first and second conduits fluidly communicating with said first and second collector sections at the respective first ends thereof;
a connection passage interconnecting said first and second collector sections, said connection passage having cross-section smaller than the cross-section of each of the collector sections; and
a valve disposed in said connection passage, said valve being arranged to be selectively openable in response to the value of an engine operational parameter exceeding a predetermined level.
Description

This is a division, of application Ser. No. 810,685, filed Dec. 19, 1985 and now U.S. Pat. No. 4,741,294.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to multi-cylinder internal combustion engines and more specifically to an induction system for such an engine which enables good inertia supercharging during both high and low engine speed operation.

2. Description of the Prior Art

FIG. 1 of the drawings shows an induction arrangement disclosed in Japanese Patent Application First Provisional Publication No. 56-115818. This arrangement as shown, comprises a single elongate collector 10 which communicates with a surge tank 12 via first and second interconnecting induction conduits 13, 14 Each of the engine cylinders #1 to #6 communicate with the collector 10 via branch runners 15a-15f. A valve 16 is disposed in the collector 10 so as to divide the same into first and second sections 10A, 10B. The first section 10A communicates with a first group of engine cylinders #1 to #3 while the second section 10B communicates with the remaining cylinders #4 to #6. When the engine is operating at low speed valve 16 is closed.

The ignition order of the first and second groups of cylinders are respectively discontinuous. Accordingly, when the engine is operating at low engine speed and the valve 16 is closed the first and second groups of cylinders aspirate through mutually independent induction systems. The dimensions of the conduiting etc., of the induction arrangement is selected so that resonance characteristics of the two "quasi" independent systems are such as to coincide with the induction pressure pulsations under low engine speed condition and thus induce good inertia ram charging (supercharging). Upon the engine speed exceeding a predetermined level valve 16 opens and induces the situation wherein the natural frequency of the single enlarged system under such conditions matches the induction pressure pulstations which occur at this time.

However, this arrangement encounters the drawback in that although the system is relatively simple, upon opening of valve 16 the charging effect provided in branch runners 15c and 15d which are located close to the valve and the charging effect provided at branch runners 15a and 15f (remote from valve 16) are not the same. Accordingly, charging efficiency varies from one cylinder to another and optimal engine performance is not obtained.

Further examples of the above type of induction system are found in Japanese Patent Utility Model First Prov. Pub. No. 58-129063 and Japanese Patent Utility Model Second Prov. Pub. No. 46-21123.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an induction system which provides good inertia supercharging characteristics under both high and low engine speed operations and wherein the variation in supercharging effect between cylinders is minimized in a manner which improves engine performance under both modes.

In brief, the above object is achieved by an arrangement wherein the cylinders of the engine are divided into first and second groups or banks wherein the ignition sequence of the respective groups is discontinuous; and wherein the induction system for supplying air to the first and second group of cylinders is characterized by: a first elongate collector section with which the first group of cylinders fluidly communicate via branch runners, the first collector section having first and second ends; a second elongate collector section fluidly discrete from the first collector section and with which the second group of cylinders fluidly communicate via branch runners, the second collector section having first and second ends; a surge tank; first and second conduits leading from the surge tank to the first and second collector sections respectively, the first and second conduits fluidly communicating with the first and second collector sections at the respective first ends thereof; connection passage leading from a location essentially mid-way between the ends of the first collector section to a location essentially mid-way between the ends of the second collector section; and a valve disposed in the connection passage, the valve being arranged to assume a closed position wherein communication between the first and second collector sections is prevented and an open position wherein communication is permitted, the valve being arranged to change from the closed position to the open position upon the magnitude of a selected operational parameter of the engine exceeding a predetermined level.

With the above defined invention it is possible to arrange an induction manifold for a V-6 engine in a manner that the collector sections are located side by side and essentially parallel with an elongate surge tank. The difference in the lengths of the conduits which interconnect the surge tank with the respective collectors with such an arrangement is compensated for by varying the volumes of the two collectors in a manner which achieves a suitable balance in resonance characteristics. By arranging the connection tube to have an essentially U-shape and to lie on top of the side-by-side collectors, a highly compact arrangement results.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the arrangement present invention will become more clearly appreciated from the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 shows in schematic form the prior art arrangement discussed in the opening paragraphs of the present disclosure;

FIG. 2 shows in schematic form the induction system arrangement which characterizes the present invention;

FIG. 3 is a sectional elevation of an embodiment of the present invention;

FIG. 4 is a sectional plan view of the induction manifold used in the arrangement shown in FIG. 3;

FIG. 5 is a sectional view taken along section line V--V of FIG. 4;

FIG. 6 is an enlarged sectional view of the valve shown in FIG. 5;

FIG. 7 is a graph showing in terms of engine torque and engine rotational speed, a comparison of the torque characteristics derived using the prior art arrangement shown in FIG. 1 and the present invention;

FIG. 8 is a graph showing in terms of engine torque and engine speed, the change in torque developed by an engine equipped with the arrangement of the present invention when the length of the connection pipe which bridges the two induction collectors is varied;

FIG. 9 is a graph also in terms of engine torque and speed showing the effect of change in diameter (viz., cross-sectional area) of the connection pipe on the engine torque characteristics;

FIG. 10 is a graph showing the effect of change of volume of the collector sections on the torque generation characteristics of the engine;

FIG. 11 is a similar graph showing the effect of induction conduit diameter (cross-sectional area) on the engine output; and

FIG. 12 is a graph showing the the effect of changing the volume of the collectors on the engine output with the cross-sectional area of the induction conduits set at a relatively small value.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before proceeding to describe an actual embodiment of the present invention it is deemed advantageous to firstly turn to FIG. 2 wherein the basic arrangement of the present invention is set forth in schematic form.

As will be appreciated the arrangement of the present invention is such that the induction manifold 100 includes induction conduits 102, 104 which lead from the surge tank 106 and communicate with the ends of collectors 108 110, and a connection pipe 112 leads from a location essentially mid-way between the ends of collector 108 to a location essentially mid-way between the ends of collector 110. The branch runners 114a-114f which communicate the two collector sections 108, 110 with the combustion chambers of cylinders #1 to #6 via induction ports 115 are arranged to branch-off from the collectors at essentially equally spaced intervals. A valve 116 is disposed in the connection pipe 112.

Experiments have shown that it is preferable to arrange for the volume the collectors 108, 110 to be in excess of half of the engine displacement. Viz., as shown in FIG. 10 given that the displacement of the engine is 3 liters (2960cc), the length of the induction conduits 102, 104 which interconnect the surge tank 106 and the collectors, is 430mm and the diameter of the same 70mm, when the volume of the collectors 108, 110 are arranged to be 0.9 liter the output of the engine is markedly lower than if the capacity thereof is slightly greater than half of the engine displacement (viz., 1, 700cc).

Experiments wherein the diameter of the induction conduits 102, 104 was varied while holding the volume of the collectors 108, 110 and the length of the induction conduits 102, 104 constant at 1.7 liter and 430mm respectively; revealed that a diameter of 70mm gave superior engine performance over an arrangement wherein the diameter was reduced to 40mm.

To confirm the above results experiments wherein the volume of the collectors 108, 110 were varied with an induction arrangement wherein the length and diameter of the induction conduits were held constant at 430mm and 40mm respectively. As shown, when the volume of the collectors was 1.7 liter the torque developed by the engine was notably better than when the volume was reduced to 0.6 liter.

As will become clear hereinlater with a discussion of the graphs of Figs. 7 to 9, by using the above described arrangement and by selecting the length and diameter of the connecting pipe 112 in conjunction with the dimensions of the remaining system, it is possible to achieve an engine performance which is notably better than that achieved with the FIG. 1 arrangement.

The diameter of the engine induction ports 115 in the engine tested was 42mm. Accordingly, from the above data it was determined that the cross-sectional area of the induction conduits should be greater than 2.5 times the cross sectional area of the induction ports 115.

Subsequent experiments (which will be dealt with in more detail hereinlater) revealed that given the above mentioned manifold specifications, it is preferable for the connection pipe 112 to be 100mm to 430mm in length (viz., 0.33 to 1.5 times the length of collectors 108, 110 and therefor about the sum of the diameters of three cylinders; and to be 40-60mm in diameter.

FIG. 8 shows the results of experiments which were conducted in order to the detect the effect of changing the length of the connection pipe 112 on the torque produced by the engine. It will be noted that the diameter of the pipe was held constant at 40mm.

As shown, all of the pipes tested showed better torque generation characteristics over an arrangement wherein the two collectors were communicated directly (viz., via a pipe having a zero length).

FIG. 9 shows the results of tests conducted to determined the optimum diameter (viz., the cross-sectional area) of connection pipe 112. During these tests the length of the pipe was held constant at 300mm. As will be appreciated the engine performance did not vary to any particular degree when pipes having 40, 50 and 60mm diameters were used. However, in order to avoid any marked changes in internal volume of the induction system it is deemed appropriate that the diameter of the pipe be arranged to close to or within the above mentioned range.

With the above described specifications when the engine is operating a low engine speeds, the resonance characteristics of the induction system with the valve 116 closed, match the pressure pulsations which occur in the induction system and induce the engine produce torque which varies as shown by chain line in FIG. 7. Upon opening of valve 116 the collectors 108 and 110 become communicated via connection pipe 112 whereby the distance of the intake system ahead of the intake ports 115 is increased by only the distance between the runners 114a and 114b so that the system becomes resonant with short wavelength pulsations which are produced under such conditions. The torque generation characteristics with the valve 116 open are depicted in FIG. 7 by the solid line trace. As will be appreciated the torque produced by the engine with the present invention is higher than that produced by the prior art arrangement shown in FIG. 1 of the drawings, the torque generation characteristics of which are denoted by the chain line trace in the same figure. The difference between the invention and the prior art which occurs with the valve open and the engine operating at high engine speed is highlighted by hatching in FIG. 7.

As will be appreciated it is advantageous to select the point at which the valve is switched from its closed position to its open one so that a sharp change in torque generation is not experienced. Viz., it is advantageous to select the changeover point to be conincident with the engine speed at which the chain line trace intersects the solid line one.

FIGS. 3 to 6 show an actual embodiment of the present invention as applied to a 2960cc displacement V-6 type engine.

In this arrangment the induction manifold 100 is arranged above and between two banks of three cylinders of a V-6 engine 300. As shown, the branch runners 114a-114f in this embodiment lead upwardly from the intake ports 302 the engine and open into the bottom their respective collector sections 108, 110. As best seen in FIG. 4 the collector sections are defined in a housing 120 which is partitioned by wall 122 which extends essentially parallel with the longtiudinal axis of the engine. The induction conduits 102., 104 blend into the ends of the collectors 108, 110 and lead to the surge tank 106.

In this arrangement, the surge tank 106 is, as best seen in FIG. 4, elongate and arranged to extend parallel to the collector housing 120. The surge tank 106 is arranged to communicate with the an air cleaner 124 via a conduit arrangment including a throttle valve 126 and an air flow meter 128 (in this embodiment the air flow meter is depicted as being, merely by way of example, a hot wire/vortex type). The connection pipe 112 in this emodiment is advantageously arranged to have an essentially U-shape (see FIG. 4 )and to lie flat on the top or "roof" of the collector housing 120. The valve 116 which has a construction as best seen in Figs. 6 is arranged to located in the U-shaped connection pipe 6 at a location adjacent the end of collector section 108. With this arrangement an actuator 130 of the valve 116 may be arranged to depend into the space available at this point (see FIG. 5).

FIG. 6 shows the construction of the valve 116 and actuator 130 in detail. In this embodiment the valve 116 includes a vane 132 which is secured to one end of a rotable shaft 134. Roller bearings 136, 138 rotatably journal the shaft 134. The actuator which may be any suitable type (viz., for example electrical, electical/mechanical, pneumatic or the like) is disposed in a cup-shaped housing 140 and between the roller bearings 136, 138.

As will be best appreciated from FIG. 5, by arranging the cross-section of the collector sections 108, 110 and induction conduits 102, 104 to be essentially rectangular in shape, the height of the induction manifold can be kept to a minimum and the arrangement rendered highly compact. Arranging the longitudinal vertical cross-section of the U-shaped connection pipe to be slightly wedge shaped tends to minimize the height increasing effect of placing the same on top of the housing 120.

In the instant embodiment the displacement of the engine is 2960cc, the volumes of the collectors 108 and 110 are 1.9 and 1.6 liters respectively (the sum being greater than the engine displacement), and the volume of the surge tank 106 is arranged to be 3 liters and thus act as the free ends of the system through which the pressure waves pass.

It will be noted that with the instant embodiment as the arrangement of the induction pasages and the collectors is not symmetrical it is necessary to vary the volumes of the collectors slightly so as to achieve a unification in the supercharging effect on the two group of cylinders. The performance characteristics of the this embodiment are essentially as shown in FIG. 7.

With the above described embodiment as the valve 112 is located at a high position the possiblity that any water which might have entered the system will not collect therein and induce the possiblity that under very cold conditions that the valve will freeze in a closed state.

It will also be noted that although the connection pipe is illustated as being cast integrally with the remaining portions of the housing 120 it is possible to provide same as a separate detachable unit.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3796048 *Sep 27, 1972May 31, 1983 Title not available
US4300488 *Jul 6, 1979Nov 17, 1981Autoipari Kutato IntezetResonator conduit system for introducing intake gases in internal combustion engines
US4510896 *Nov 4, 1983Apr 16, 1985Dr. Ing. H.C.F. Porsche AktiengesellschaftMulti-cylinder combustion engine intake manifold
US4513699 *Feb 22, 1983Apr 30, 1985Autoipari Kutato Es Fejleszto VallalatIntake gas resonance system for internal combustion engines
US4527392 *Apr 18, 1983Jul 9, 1985Hino Jidosha Kogyo Kabushiki KaishaBypass valve actuator for inertia supercharging in multicylinder engines
US4630575 *Aug 22, 1985Dec 23, 1986Mazda Motor CorporationIntake system for multicylinder engine
JPS56115818A * Title not available
JPS59126027A * Title not available
JPS59126028A * Title not available
JPS60222524A * Title not available
JPS60230510A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4957071 *Jul 25, 1989Sep 18, 1990Nissan Motor Co., Ltd.Intake system for V-type internal combustion engine
US4974568 *Oct 4, 1989Dec 4, 1990Autoipari Kutato Es Fejleszto VallalatResonance system with variable geometry for the fresh-gas conduit for internal combustion engines.
US5040495 *Dec 28, 1989Aug 20, 1991Mazda Motor CorporationSuction apparatus for engine
US5056473 *May 29, 1990Oct 15, 1991Honda Giken Kogyo Kabushiki KaishaIntake device for multi-cylinder internal combustion engine
US5156116 *Dec 16, 1991Oct 20, 1992Mercedes-Benz AgMethod and apparatus for controlling the air supply in an internal combustion engine
US5921212 *Jun 28, 1996Jul 13, 1999Ab VolvoIntake system for multi-cylinder combustion engines
US6516768 *Sep 18, 2000Feb 11, 2003Sanshin Kogyo Kabushiki KaishaFour-cycle engine
US6557511 *Aug 3, 2001May 6, 2003Dr. Ing. H.C.F. Porsche AktiengesellschaftSuction system
DE10128721B4 *Jun 13, 2001Nov 17, 2005Siemens AgVorrichtung zur Aufladung einer Brennkraftmaschine
Classifications
U.S. Classification123/184.49, 123/184.36
International ClassificationF02B27/02, F02B75/22, F02B75/20, F02B75/18
Cooperative ClassificationY02T10/146, F02B75/22, F02B75/20, F02B2275/20, F02B2075/1824, F02B27/021, F02B27/0242, F02B27/0252
European ClassificationF02B27/02, F02B75/22
Legal Events
DateCodeEventDescription
Sep 28, 2000FPAYFee payment
Year of fee payment: 12
Sep 26, 1996FPAYFee payment
Year of fee payment: 8
Sep 24, 1992FPAYFee payment
Year of fee payment: 4